In such known circuit-breaker control apparatus, disengagement is performed by means of the disengagement spring assembly which is constituted by a helical spring that is coaxial with the drive rod, with one of its ends pressed against a fixed portion, and with its other end pressed against the first slide, the spring being held compressed in the circuit-breaker disengaged position by the control means constituted by retractable slide-retaining means for retaining the slide. On disengagement, said slide-retaining means are retracted, and the released spring drives the slide and therefore the tubular arm, thereby driving the drive rod and opening the contacts of the circuit-breaker. On engagement, the drive is provided by the solenoid on its own, with the tubular arm driving the slide against the force of the spring which is re-compressed until it is latched by the retaining means, and also driving the drive rod to the engaged position in which the contacts are closed.
That type of control suffers from the drawback that it is dangerous on engagement, because the drive for performing such engagement is provided by the solenoid on its own, and if a malfunction occurs in the solenoid, the contacts might not be closed, or, in particular, they might be closed abnormally.
The present invention solves this problem by providing apparatus such that the control end of the drive rod is coupled to the tubular arm via at least one projecting portion fixed to the drive rod and passing through a respective longitudinal slot provided along the tubular arm, and such that the control apparatus includes an "engagement" second slide to which the drive rod is fixed via its projecting portion, the engagement second slide being subjected to an "engagement" second spring assembly which displaces it from the circuit-breaker disengaged position to the circuit-breaker engaged position under the action of second control means actuated on engagement.
In a first variant embodiment of the first spring assembly, said first spring assembly is constituted by a helical spring which is coaxial with the drive rod, and which has one of its ends pressed against a first fixed portion and its other end pressed against the first slide, the first spring being held compressed in the circuit-breaker engaged position by the first control means constituted by retractable slide-retaining means for retaining the first slide.
In a second variant embodiment of the first spring assembly, said first spring assembly is constituted by two telescopic arms which have their longitudinal axes lying in the same plane, each one of the facing ends of the arms being connected to the first slide via a respective pivoting link, and the other end of each arm being pivotally fixed to a respective fixed point, a spring surrounding the arm being compressed between the pivoting link and the fixed end, and the first control means are preferably constituted by a drive member for driving the first slide.
In a first variant of the second spring assembly, said second spring assembly is constituted by a helical spring which is coaxial with the tubular arm, and which has one of its ends pressed against a second fixed portion and its other end pressed against the second slide to which the drive rod is fixed via its projecting portion, the second spring being held compressed in the circuit-breaker disengaged position by the second control means constituted by retractable slide-retaining means for retaining the second slide.
In a second embodiment of the second spring assembly, said second spring assembly is constituted by two telescopic arms which have their longitudinal axes lying in the same plane, each one of the facing ends of the arms being connected to the second slide via a respective pivoting link, and the other end of each arm being pivotally fixed to a respective fixed point, a spring surrounding the arm being compressed between the pivoting link and the fixed end, and the second control means are preferably constituted by a drive member for driving the second slide.